Safety device for die-presses and analogous machines.



H. G. H. WALSH.

SAFETY DEVICE FOR DIE PRESSES AND ANALOGOUS MACHINES.

Patented Dec. 17,1912.

4 SHEETSSHEET 1.

APPLICATION FILED OUT. 26, 1911.

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H. 0. H. WALSH. SAFETY DEVICE FOR DIE PRESSES AND ANALOGOUS MACHINES.

APPLICATION FILED OCT. 26, 1911. 1,047,349., Patented Dec. 17,1912.

4 SHEETS-SHEET 2.

H. G. H. WALSH.

SAFETY DEVICE FOR DIE PRBSSBS AND ANALOGOUS MACHINES.

APPLICATION FILED OUT. 26, 1911.

Patented Dec. 17 1912.

4 SHEETS-SHEET 3.

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H. 0. H. WALSH. SAFETY DEVICE FOR DIE PRESSES AND ANALOGOUS MACHINES.

, APPLICATION FILED OCT. 26, 1911. 1,047,349. Patented Dec.17,1912.

4 SHEETS-SHEET 4.

- whether it was in operative condition at the Fig. 1 and looking downwardly; Fig. 3 is UNITED STATES PATENT OFFICE.

HARRY C. H. WALSH, OF CHICAGO, ILLINOIS, ASSIGNOR OF 0NE-HALF TO VANCE 1?.

WILKINS, OF LAPORTE, INDIANA.

SAFETY DEVICE FOR DIE-PRESSE S AND ANALOGOUS MACHINES.

To all 20720122- 1' z m ay concern Be it known thatv I, HARRY C. H. TALSH, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Safety Devices for Die-Presses and Analogous Machines, of which the following is a specification;

This invention relates to improvements in safety devices for die presses and analogous machines, and has for its salient objects to provide an attachment, adapted to be applied to almost any standard die press, which makes it imperative for the operator to employ both hands at a point outside of the range of operation of the dielstamp at the time the latter descends and therefore makes it impossible for the operator to be accidentally injured; to provide a device which is positive and certain in its operation, thus avoiding controversies as to time of the accident; to providea device of the character referred to which cannot be tampered with and'rendered temporarily inoperative by the workman; to provide an apparatus which may be purposely-locked out of operative conditionat the will of the foreman; to provide a device so constructedthat a partial return of the trip mechanism, or mechanism which controls the operation of the press, will nevertheless not. disturb the effective guarding functions of the apparatus; and in general, to provide improvements in an apparatus of the character referred to. I

To the above ends the invention consists in the matters hereinafter described, and moreparticularly pointed out in the appended claims.

In the drawingsFigure l is aside elevation (the top portion being broken off) of a press equipped with my improved safety device; Fig. 2 is a horizontal sectional view, taken approximately on line 2-2 of a transverse sectional view, taken on line 3 3 of Fig. 2 and looklng 1n the direction of the arrows; Fig. 4 is a detail of parts of the clutch controlling mechanism of the die press; Fig. 5 is a view chiefly in axialsec- E tion of the parts shown in Fig. 4; Fig. 6 is a detail, with'parts in section, of the safety locking mechanism; Fig. 7. is aneni larged sectional detail of a locking mechai Specification of Letters Patent.

nism whereby the safety apparatus may be shown in Fig.6; Fig. 11 is a. view, partly Patented Dec. 17, 1912.

Application filed October 26, 1911. Serial No. 656,941.

in section, of a modification of the -trip-fi member construction; Fig. 12 is a. cross-sec tion on line 12-12 of Fig. 11.

Referring to the drawings, 1 designates as a whole the main frame of an ordinary die press" having the vertically reciprocatory plunger 2. working toward and from the bed .plate 3; the descent of the plunger be- I ing determined primarily by a. foot treadle 4,'which when depressed, through the medium of a rod 5, draws down the oscillat ing lever 6, and this in turn draws down rod 7 which controls the clutch latch 8. That is to say, assuming the fly-wheel of the press to be running constantly, a downpull on the clutch latch 8 withdraws it from under the bolt actuating lever 9 (Fig. 5). which thereupon under the action of the spring plunger 10 oscillates and projects the clutch bolt 11 into the hub 12 of the main shaft. Thereupon the main shaft makes one revolution, throwing the die plunger down once and automatically throwing itself out of gear at the end of a single revolution. These are the ordinary operations of such 7 a press.

Coming now to a description of the safety device, upon the front side of the bed plate is suitably mounted a casing 13. and inside this casing at about the center thereof isis normally maintained in normal or centered position by means of spring-pressed studs or plungers 19 which engage the under sides thereof and the heads of which plungers work in spring barrels containing expansion springs 21. The upstanding arm 16 of lever 14 connects with a link 22 which extendslaterally out through the casing and across the front of the bed of the press to the angle of .the latter and there connects with a second bell-crank lever 23. The lat-- ter lever is pivotally mounted in a rightangled coupling 24 which at .its respective ends connectswith pipecasings 25 and 26; the pipe 25 being threaded onto a suitable nipple 27 on the main cas'ng 13 of the trip lever, while the end of pipe 26 connects with a lock-bolt casing 28, now to be described. A slot 16 provides lost motion between parts 16 and 17. The lock-bolt casing 28 is bolted to the side of the'press and is transversely apertured to provide a boltsocket 29 in which works a locking bolt 30. This locking bolt is mounted on the end of a link 31 extending through the pipe casing 26 and at its other end connected with the belLcrank lever 23. A coiled expansion spring 32 interposed between the end of the Y be observed that the loclebolt casing 28 is prolonged so as to overlap the jaw space between the lock-bolt and lever and is also extended above the upper side of the lever so as to prevent a workman-from tampering with the locking mechanism by inserting a strip or other obstacle between the lever and locking bolt in such manner as to prevent the latter from engaging. It will also be noted that the working mechanism of the 'safety device is all similarly incased to prevent tampering; the only accessible parts to said mechanism being the push buttons.

To make certain the interengagementof the teeth of bolt 30 and lever 6, link 7 is provided with a slightly yielding coupling 39.

The operation is as follows: The operator.

having placed an article in position between the dies before operating the foot treadle, must. first depress the two push buttons a, b. The distance between these push buttons is more than a hands span, compelling the use of both hands in order to depress the two push buttons simultaneously. By depressing them simultaneously the lever 17 is moved down bodily and, so

operates the train of connections to withdraw the locking bolt 30 from the lever 6.

He may then depress the treadle and start the press. Should he attempt to operate by depressing one push button only, the trip lever oscillates ldly on its pivot 17, the op.-

be held from rising-and the other depressed,

the lost motion slot 16 .prevents effective operation. When, however, both push buttons are pressed together, by their cumulative action on the trip member, the bell-crank 14 is oscillated positively and operates torelease the lock.

To look the appliance out of commission, I- have provided a locking screw stud 33 mounted in a casing 3 1 which is threaded or otherwise secured in an aperture 35 in the front wall of the casing 13; the location of these parts being'such that the screw stud 33 can be projected above the central part of the trip lever 17 when the latter is depressed (see detail Fig. 7). An escutcheon plate 36 forms a rotatable closure for the outer end of the stud casing 34; this 'escutcheon plate being. provided with an unusual shaped keyhole 37, the screw stud 33 is provided with a similar keyhole to receive the end of the key inserted through the esc'utcheon whereby the screw stud may be rotated and thus projected or retracted.

In Fig. 10 I have shown a slight modification of the locking mechanism which controls the lever 6. In this modified construc tion the locking casing 28 is of somewhat different shape. and incloses a bell-crank lever 38 pivotally mounted at its angle within the casing and connected as to its upstanding arm to the link 31, The other arm 38 of the bell-crank lever constitutes one member of the toggle acting friction clutch and is adapted to impinge against the end face of the lever 6. That is to say, the pivot pins or supports of the levers 38 and 6 are so related to each other that the locking arm 38' engages the end of lever 6 before said levers reach a position in exact alinement with each other upon a downward movement, whereupon frictional engagement occurs and the associated parts form a toggle acting friction look. This form of lock will,

of course, operate to lock the lever 6 at any height, to which it happens to be moved. The locking lever 38 is withdrawn to release lever 6 by the same mechanism described and shown in the preceding figures of the drawings.

It is to be particularly noted that the safety attachment is so organized and located that it does not interfere in. the slightest with the manipulation of the work being done-.011 the press, nor does it interfere with the movements of, the operator in placing the work under the dies and removing the same. Moreover, the push buttons are solocated that they are in precisely the most convenient position for the 'operators hands when he withdraws his hands in a natural way after placing an object in position under the dies. So also it is to benoted that the push buttons cannot he accidentally 5 operated because they are both flush with the casing and must both be depressed to gether in order toaccomplish the unlocking of the treadle-operated mechanism. Again it is to be particularly noted that if the operator is careless about releasing his pressure on the foot treadle so that the control ling lever 6 only returns part way to its normal upper position, it is nevertheless locked in whatever position it may be against downward movement, and the operator cannot therefore accidentally make the press repeat, an operation which is usually much more dangerous than the normal operation of the press, because unexpected. It is to be noted also that the operation of the safety'apparatus is to all intents and purposes operative in both directions. That is to say, it automatically locks the instant it is released, and in a manner beyond the control of the operator except through the push buttons. Likewise pressure upon the two push buttons simultaneously positively withdraws the locking bolt. The incasing of the operative mechanism insures that the Workman cannot secretly fasten the safety device out of commission when the foreman is not around and then readily restore it to commission when he fears that theforemalr may catch him. The fact that the mechanism. is tamperproof as against allvordinary expedients of tampering is, of course, likely to be a matter of vital importance both in preventing accidents and in determining who was responsible in case of accident.

In Figs. 11 and 12 I have shown a modi-' fication of the trip-member, which in this instance is so organized that it is compulsory upon the operator to depress both push buttons simultaneously, and an attempt to depress one in advance of the other locks the trip-member so that the following end of it cannot be depressed. In these figures the trip-member 40 is provided in its upper edge with a C-shaped recess 11 located atthe center of the lever and cooperating with a fi-Xed stud42 mounted in-a depending part of 'the top casing, as seen clearly in Fig. 12. The entrance opening 41 of the recess 41 is barely wide enough to permit the stud 43 to pass into the recess, the recess proper being. however, of somewhat larger diameter than the stud. In this construction the lost motion between the trip-member and the connected bell crank lever is omitted. The lock for locking the apparatus out of commission may conveniently be made as before described and so located that when the tripmember 40 is fully depressed the locking stud of the lock will engage the recess 41.

The operation of this trip-member is as follows: When the two ends thereof are depressed equally and together the stud 42 in no wise interferes. If, however, ohe end or the other of the trip-member be depressed first, the oscillation of the lever out of level carries the overhanging parts of the recess vertically above the stud 42 sufliciently to lock the other end against depression. It is, therefore," impossible for the operator, to fasten one end of the trip-member down and then use the device as a single handed release. a

\Vhile I have herein shown and described preferred embodiments of the invention it is nevertheless to be understood that the details of construction and arrangement may be substantially varied without departing from the invention as intended to be defined in the broader claims. 1

I claim as my invention:

1. The combination with a die press or analogous machine tool provided with a work-supporting bed, anoverhanging vertically reciprocatory tool member and a work space bet-ween the normal upper position of the tool member and the bed, of a safety appliance comprising alocking member adapted to lock the machine out of gear,

a push button mechanism mounted atthe 5 front of the bed of the machine comprising a'pair of push buttons spaced apart a distance greater than a hand-span, associated ,mechanism functionally inoperative by the sole operation of either push button and fully operative by the joint action of both push buttons, and mechanical connections extending from said latter mechanism to said lock.

2. The combination with a die press or analogous machine tool provided with a work-supporting bed, an-overhanging vertically reciprocatory tool member and a work space between the normal upper posi: tion of the tool member and the bed, of a safety appliance comprising a locking member adapted to lock the machine out of gear,

a trip member movably mounted, a pair of operating members separated farther than a hand-span apart and each operatively con- 1 5 nected with said trip member to move the latter and when operated togethertoimpart. cumulative movement thereto, and mechanical connections extending from said trip member to said lock.

3. The combination with a die press or analogous machine tool provided with a work-supporting bed, an overhanging ver-' tically reciprocatory tool member and a work space between the normal upper position of the tool memberandthe bed, of asafety appliance comprising a locking member adapted to lock the machine out of gear,

a trip member movably mounted. a pair of push buttons separated farther than a handto'said lock, and a casing inclosing the operative parts of said safety appliance, except the push buttons, to render the appliance tamper-proof.

4. The combination with a die press or analogous machine tool provided with a work-supporting bed, an overhanging vertically reciprocatory tool member, clutchshifting mechanism, ,and a Work space between the normal upper position of the tool member and the bed, of a safety appliance comprising a locking member mounted in juxtaposition to the clutch-shifting mechanism and adapted tolock the latter against movement, a trip member yieldably supported so as to be susceptible of both bodily and oscillatory movements, a lever pivotally connected with the intermediate part of said trip member and adapted to be moved by the latter proportionately to the bodily movement of the trip member, link connections extending between and connecting said lever with the locking member, and

finger-holds upon orconnected with said trip member, spaced more than a hand-span apart and whereby bodily movement may be imparted to the trip member.

5. The combination with a die press or analogous machine tool provided with a Work-supporting bed; an overhanging ver ticallyreciprocatory tool member, clutchshifting mechanism, and a work space betweenzthe normal upper position of the tool member and the bed, of a safety appliance comprisinga locking member mounted in uxtaposition to the clutch-shifting mechanism and adapted to lock the latter againstlmovement, a trip member yieldably supported so as to be susceptible of both bodily and oscillatory movements, a lever pivotally connected with the intermediate part of said trip member and adapted to bemoved by the latter roportionately to the bodily movement of the trip member, link connections extending between and connecting said lever with the locking member, and finger- I of said safety appliance mechanism, except only the finger-holds, being inclosed in suitable casings so as to be tamper-proof. I

6. The combination with a die'press or analogous machine tool provided with a work-supporting bed, an overhanging vertically reciprocatory tool member, clutch mechanism, a foot-treadle connected to said clutch mechanism, and a work space between the normal upper position of the toolmemprising a lock casing fixedly mounted upon the frame of the press ad acent to a part of the treadle connection between the foot treadle and clutch mechanism of the press, a locking member substantially inclosed within said lock casing and adapted to act upon said part of the treadle connection to lock the machine out of gear, a trip member casingmounted upon the front of the bed of the press, a trip member yieldably mounted upon the spring supports inside said casing and provided at each end with upstanding portions or extensions constituting push buttons which are exposed through the top side of said. casing, an angle lever operatively connected with the intermediate part of said trip member as to one of its arms and pivotally mounted upon a suitable support, and operative connections extending from the second arm of said angle lever to said locking part; the train of connections between the trip member. and the aforesaid locking part including a. lost motion connection vwhereby a partial movement of the trip member is ineffective to release the a locking part.

7. The combination with a die press or analogous machine tool provided with a work-supporting bed, an overhanging vertically reciprocatory tool member, clutch mechanism, a foot-treadle connected to said mechanism, and a work space between the normal upper position of the tool member and the bed, of a safety appliance, comprising a lock casing fixedly mounted upon the frame of the press adjacent to a part of the treadle connection between the foot treadle and clutch mechanism of the press,- alocking member substantially inclosed within said lock casing and adapted to act upon said part of the treadle connection to lock the machine out of gear, a trip member casing mounted upon the front of the bed of the press, a trip member yieldably mounted upon thespring supports inside said casing and provided at each end with upstanding portions or extensions constituting push buttons which are exposed through the top side of said casing, an angle lever operatively connected with the intermediate part of said trip member as to one of its arms and pivotally mounted upon a suitable support, and operative connections extending from the second arm of said angle lever to said locking part; the train of connections between the trip member and the aforesaid locking part including a lost motion connection whereby a partial movement of the trip member is ineffective to release thelocking part, and casings inclosing said train of connections between the trip member and locking part.

8. In combination with a die analogous machine, a two-hande ress or safety controlling mechanism, comprising a lock adapted to normally hold the machine out of operation, lock-operating mechanism associated with the lock-and comprising a pair of triggers mounted farther apart than a hands-span so as to be incapable of being both simultaneously operated by one hand, and a trigger-controlled member adapted to release said look when operated by both triggers acting conjointly, the movement of said member effected by each trigger being cumulative to that of the other and either trigger alone being incapable of releasing the lock.

9. In combination with a die press or analogous machine,' a two-handed safety mechanism comprising locking mechanism adapted to normally look the machine out of gear, lock-operating mechanism associated with the lock and comprising a pair of manually movable members mounted farther apartthan a hand-span, so as to be incapable of being simultaneously operated by one hand, a member operable by said manually operable members, operative connections between said latter member and the lock mechanism, and a casing inclosing substantially w all of the operable parts of said safety mechanism, except the manually operable members thereof.

10. In combination with a die press or analogous machine, a two-handed safety controlling mechanism, comprising a lock adapted to normally hold the machine out of operation, lock-operating mechanism associated with the lock and comprising means inter-dependently controlled by two triggers and. functionally inoperative except through the joint action of both said triggers, and a guarding casing inclosing said controlling mechanism and rendering all parts thereof tamper-proof, except the parts of said triggers exposed for normal manipulation.

In witness whereof, I hereunto subscribe my name this 19th day of October, A. D. 1911.

HARRY C. H. WALSH.

Witnesses:

'EMILIE Rose,

ALBERT H. GRAVES. 

